Improve find of grass on FreeBSD

cmake/FindGRASS.cmake

@@ -159,12 +159,20 @@ ENDIF (WIN32)
 
 IF (UNIX)
   IF (GRASS_FIND_VERSION EQUAL 7)
-    FOREACH (PATH /usr/lib64 /usr/lib /usr/local)
-        FOREACH (VERSION grass70, grass71, grass72)
-            LIST(APPEND GRASS_PATHS "${PATH}/${VERSION}")
-        ENDFOREACH (VERSION)
-    ENDFOREACH (PATH)
-  ENDIF ()
+    IF (CMAKE_SYSTEM_NAME STREQUAL "FreeBSD")
+        FOREACH (VERSION_MINOR 0 1 2 3 4)
+            FOREACH (VERSION_BUILD 0 1 2 3 4 5)
+                LIST (APPEND GRASS_PATHS /usr/local/grass-${GRASS_FIND_VERSION}.${VERSION_MINOR}.${VERSION_BUILD})
+            ENDFOREACH (VERSION_BUILD)
+        ENDFOREACH(VERSION_MINOR)
+    ELSE (CMAKE_SYSTEM_NAME STREQUAL "FreeBSD")
+        FOREACH (PATH /usr/lib64 /usr/lib)
+            FOREACH (VERSION grass70, grass71, grass72)
+                LIST(APPEND GRASS_PATHS "${PATH}/${VERSION}")
+            ENDFOREACH (VERSION)
+        ENDFOREACH (PATH)
+    ENDIF (CMAKE_SYSTEM_NAME STREQUAL "FreeBSD")
+   ENDIF (GRASS_FIND_VERSION EQUAL 7)
 ENDIF (UNIX)
 
 IF (APPLE)